I am using Django 1.3.7 and python 2.7.6 on windows7 I got an error when I executing my manage.py in this line of code
import shutil, sys, virtualenv, subprocess
Install virtualenv using pip install virtualenv. If you have it already installed, try reinstalling it by removing it with pip uninstall virtualenv and then reinstalling it. Good Luck.
pip install virtualenv
pip uninstall virtualenv